In a production workshop, e.g. for producing sheet metal assemblies, workstations are increasingly being organized into manufacturing islands which perform shaping and assembly operations on a subassembly being assembled. To make up subassemblies or assemblies, the parts to be assembled together are placed on supports that can be of different types. When such supports are voluminous and specific to a given series of assembly operations, they are referred to as "pallets". Such pallets are assigned to a given island, and only the parts travel from island to island. For the purposes of transporting the pallets within an island, pallet conveyors are often used serving the various workstations. Sometimes, it can be useful to implement one or more conveyor intersections for serving the various workstations and/or for feeding one or more pallets onto a main conveyor or removing one or more pallets therefrom. Intersections are thus obtained, each of which is constituted by a central portion connected to the various conveyor pallet-way portions that are generally perpendicular to one another. Switching the pallets onto the various pallet-way portions requires special intersection apparatus as provided by the present invention.
More particularly, in modern workshops, it must be possible to adapt each island to enable different types of subassemblies or assemblies to be assembled, so that each island has various pallets suited to the various types of subassemblies arriving at the work island. In order to enable a determined pallet to be placed on a conveyor, a pallet magazine is currently used disposed transversely to the conveyor. Such a magazine is generally implemented in the form of a carriage or traverser having a translation axis that is substantially perpendicular to the direction of the conveyor. The traverser is associated with a driving control member which enables it to be displaced transversely so as to place the appropriate pallet on the conveyor. The conveyor is itself provided with drive means for driving the pallet, e.g. drive means constituted by a self-propelled carriage including means for coupling it to the selected pallet and means for guiding it and driving it in translation along the main pallet way, so as to place the pallet in the various positions associated with the various workstations in the island.
However, in that type of apparatus, the mass of the traverser plus the pallets that it displaces makes it necessary to provide drive means that are powerful and therefore costly. In addition, the large mass results in operating inertia which increases the response time required by the traverser to respond to the instructions that are transmitted to it, which slows down the pallet change-over process.
It therefore appears to be useful to design pallet change-over apparatus having a simpler structure, and having moving parts with less inertia. An object of the invention is therefore to provide pallet change-over apparatus for a pallet conveyor.